1. Field
The present teachings relate generally to locking differentials for vehicles and, more specifically, to features of a locking differential having preload spring wear pads.
2. Description of the Related Art
Locking differentials of the type contemplated by the present teachings are employed as a part of a drive train and generally include a pair of clutch members supported for rotation in a housing. A pair of side gears are splined for rotation to corresponding axle half shafts. A clutch mechanism is interposed between the clutch members and the side gears. A cross pin is operatively mounted for rotation with the housing and is received in a pair of opposed grooves formed on the inwardly facing surfaces of the clutch members. In an event requiring differential rotation between the axle half shafts, such as cornering, the higher speed axle shaft advances its clutch to an over-running condition, decoupling it from the powertrain torque. If the driving terrain provides insufficient traction to activate the over-running feature of the locking differential, or while driving in a straight line, torque is applied equally to both axle shafts.
While locking differentials of this type have generally worked for their intended purposes, certain disadvantages remain. More specifically, internally pre-loaded locking differentials typically use compression springs to provide the necessary slip resistance on the clutch packs to energize a ramping effect of the clutch members to cross pin interface. Given the required relative motion between the clutch members, the compression spring is “worked” between the two components. This motion causes “sliding” wear to both the compression spring and the clutch members. The interaction can also cause binding of the coils of the compression spring to the edges of the corresponding cavity or pocket. These conditions result in unintended forces acting within the interface that can increase the propensity of the differential being damaged.
Thus, there remains a need in the art for a locking differential that is designed so as to achieve control of the interaction of the clutch members and compression springs, thereby providing for smoother operation and reduced spring binding and breakage.